Zolpidem (Ambien®) versus Temazepam (Restoril®)
Based on "Sleep Disorders Medicine"
written by Dr. Sudhansu Chokroverty, MD
Difference between Zolpidem and Temazepam
Zolpidem, a short half-life non-benzodiazepine, versus temazepam, a medium half-life benzodiazepine, comparison chart:
|Brand name/Year of initial approval||Ambien®, 1992||Restoril®, 1981|
|Formulations||Oral tablets, sublingual tablets, oral spray||Oral capsules|
|Legal status||Schedule IV
|Drug class||Bon-benzodiazepine sedative-hypnotic, short-acting||Benzodiazepine receptor agonist, intermediate acting|
|FDA-approved Indications||• Short-term treatment of insomnia, generally for sleep-onset insomnia||• Short-term treatment of insomnia (generally 7 to 10 days).|
|Mechanism of action||• Zolpidem facilitates GABAergic neurotransmission through a positive allosteric modulation of GABA (A) receptors.||• Non-selective modulation of GABA to increase GABA affinity for GABA receptor|
|Half-life||2.5-3 hours||8.8 hours (range from 3.5 to 18.4)|
|Metabolism, Elimination||Hepatic metabolism, converted to inactive metabolites, which are excreted by the kidneys.
Elimination of the drug is slower in patients with chronic renal insufficiency.
|No hepatic metabolism. Metabolized via conjugation.
80-90% of unchanged drug is excreted in the urine, 10% in the feces.
|Contraindications||• Hypersensitivity||• Pregnancy
|Warnings & precautions||• Severe anaphylactic reactions||• Severe anaphylactic reactions
• Use with caution in severely depressed patients or those with sings of latent depression
|Abnormal behaviors||May cause complex sleep-related behaviors such as sleep-eating or sleep-driving with no memory of the event.|
|Side effects||• Dizziness, drowsiness, confusion, headache, nausea, diarrhea, hallucinations, sleepwalking, amnesia.|| • Hemodynamic side effects, orthostatic hypotension3
• Drowsiness, fatigue dizziness, daytime impairment, hangover
|Rebound insomnia||Zolpidem has no advantages over temazepam with respect to rebound insomnia2.|
|Driving ability after-midnight intake||Both zolpidem and temazepam do not produce significant residual side effects on psychomotor performance 4.|
|Effects on physical performance capacity||Single dose of either hypnotic does not negatively affect physical performance characteristics6.|
|Abuse, physical dependence, tolerance||Zolpidem has lower risk for abuse, withdrawal, and tolerance compared to non-selective benzodiazepines|
|Drug interactions||Increased sedation and depressive effects when taken with other CNS depressants.|
Can cause teratogenic effects on fetuses
|Onset of sedative effect||Rapid onset||Delayed onset|
|Time to maximal drug effect 1||0.5-1.0 hours||2-3 hours|
|Advantages||• Preferred hypnotic for people with problems falling asleep
• Sublingual zolpidem is a good choice for middle of the night wakening
• Less hangover effect
• Lower risk of tolerance and withdrawal
|• Temazepam may be useful for concomitant anxiety.
• May be preferred hypnotic for insomniacs with liver disease.
• Due to longer half-life temazepam may be a better choice than zolpidem for insomniacs who awaken frequently (sleep maintenance insomnia)
|Disadvantages||• More likely to cause hangover
• Slow gastrointestinal absorption compared to other sedative
• Temazepam has a slow onset of action and is not a ideal choice for sleep-onset insomnia
Zolpidem is an imidazopyridine hypnotic that is biochemically distinct from classic benzodiazepines in that it may be selective for the BZ1 receptor subtype and shows a different pattern of distribution of binding sites1. Zolpidem lacks anxiolytic, muscle relaxant and anticonvulsant actions.
|Results of double-blind study of efficacy of zolpidem versus temazepam in transient insomnia 5||Zolpidem||Temazepam|
|Dose regimen||10 mg 15 min before lights out||15 mg 15 min before lights out|
|Hypnotic effects||Reduced awakenings and wake after sleep onset|
|Improved sleep efficiency and subjective sleep measures|
|Symbol copying test, morning sleepiness, morning concentration||Not affected|
|Digit symbol substitution test||Significantly reduced morning test performance|
- 1. Rush CR, Griffiths RR. Zolpidem, triazolam, and temazepam: behavioral and subject-rated effects in normal volunteers. J Clin Psychopharmacol. 1996 Apr;16(2):146-57. PubMed
- 2. Voshaar RC1, van Balkom AJ, Zitman FG. Zolpidem is not superior to temazepam with respect to rebound insomnia: a controlled study. Eur Neuropsychopharmacol. 2004 Aug;14(4):301-6. PubMed
- 3. Shi SJ, Garcia KM, Meck JV. Temazepam, but not zolpidem, causes orthostatic hypotension in astronauts after spaceflight. J Cardiovasc Pharmacol. 2003 Jan;41(1):31-9. PubMed
- 4. Partinen M1, Hirvonen K, Hublin C, Halavaara M, Hiltunen H. Effects of after-midnight intake of zolpidem and temazepam on driving ability in women with non-organic insomnia. Sleep Med. 2003 Nov;4(6):553-61. PubMed
- 5. Erman MK, Erwin CW, Gengo FM, et al. Comparative efficacy of zolpidem and temazepam in transient insomnia. Hum Psychopharmacol. 2001 Mar;16(2):169-176. PubMed
- 6. Gremion G, Sutter-Weyrich C, Rostan A, Forster A. Physical performance and sedation: comparative study of the effects of a benzodiazepine (temazepam) and of a non-benzodiazepine hypnotic (zolpidem). Schweiz Z Sportmed. 1992 Sep;40(3):113-8. PubMed
Published: November 24, 2016
Last updated: November 28, 2016